Personally I have increased the time before it switches off to minimise rinsing, before it would switch off after 30min now 3h.

Yes, you can of course make a single cup. Regarding water, many machines rinse, even the best seller Delonghi ECAM. So it's unfortunately not too avoidable.

When the machine is switched on and off, it self-cleans, which means that the same amount of water will be wasted for one cup of espresso. This model is more interesting for several users at the same time.